Merge branch 'core-updates'

.gitignore

build-aux/check-available-binaries.scm

build-aux/check-final-inputs-self-contained.scm

build-aux/download.scm

doc/guix.texi

gnu-system.am

gnu/packages/apr.scm

gnu/packages/autotools.scm

gnu/packages/base.scm

gnu/packages/bash.scm

gnu/packages/boost.scm

gnu/packages/bootstrap.scm

gnu/packages/bootstrap/armhf-linux/bash

gnu/packages/bootstrap/armhf-linux/mkdir

gnu/packages/bootstrap/armhf-linux/tar

gnu/packages/bootstrap/armhf-linux/xz

gnu/packages/commencement.scm

gnu/packages/compression.scm

gnu/packages/cross-base.scm

gnu/packages/curl.scm